The present invention relates to the structure of a casing for a radio pager, radio telephone or similar miniature portable apparatus.
Portable apparatuses which are miniature and light weight are extensively used today and include radio pagers and radio telephones. This kind of apparatus has a casing accommodating various functioning parts. The casing has customarily been made up of a box-line case storing the functioning parts, and a cover covering the open end of the case. To couple the case and cover, a rib provided on the case and a rib provided on the cover are caused to mate with each other, and then the case and cover are fastened by, for example, a screw.
The problem with the conventional casing described above is that when a torsional load or similar unexpected load acts on the casing, the cover is apt to shift relative to the casing or even to separate from the casing.